Brush chipper

ABSTRACT

Apparatus for reducing material such as limbs, branches, brush and the like to chips wherein a reversible powered feed mechanism moves the material in a longitudinal feed path to a statically balanced, rotary chipping mechanism having a chipping disc mounting only a single, generally radially disposed, chipping knife which is angularly disposed relative to the feed path to draw the material forwardly. The apparatus also includes drive mechanism operating the feed mechanism and disc at a correlated rate which considers the angular disposition of the single knife to move material to the disc at an optimum rate causing the knife to reduce the material to chips.

[ Jan. 21, 1975 BRUSH CHIPPER Primar ExaminerR0 Lake 5l t:L d.SthR ,Mh. Y Y [7 men or ewar N ml emus Assistant ExaminerE. F. Desmond [73] Morbark Industries, Inc., Winn,

Mich.

Assignee: Attorney, Agent, or FirmLearman & McCulloch [57] ABSTRACT Apparatus for reducing material such as limbs,

[22] Filed: July 6, 1973 [21] Appl. No.2 376,959

branches, brush and the like to chips wherein a reversible powered feed mechanism moves the material in a longitudinal feed path to a statically balanced. rotary chipping mechanism having a chipping disc mounting only a single, generally radially disposed, chipping knife which is angularly disposed relative to the feed path to draw the material forwardly.

., 8 00 0M7 00 2 07 2 2 1. 11 2 44 8 22 2 H 2 1 4 (5J2 2 u 7m WW7.

u m II C lo rm 5 W U IF 1] 2 00 5 55 .l [rt The apparatus also includes drive mechanism operating the feed References Clted mechanism and disc at a correlated rate which con- UNITED STATES PATENTS siders the angular disposition of the single knife to 885,177 Powell 241/92 move material to the disc a an opt ate causing 1,947,728 the knife to reduce the material to chips. 2,712,903 3,000,411

2/1934 Mitchell..................,. 7/1955 9/1961 30 Claims, 5 Drawing Figures Dettmering et al.......

PATENTH] JAN 21 I975 SHEET l 0F 3 PATENTED JAN21 I975 SHEEI 2 OF 3 FIG?) BRUSH CIIIPPER BACKGROUND OF THE INVENTION This invention relates to chippers mounted on portable, wheeled frames which may be drawn behind a truck or the like and which are intended for use by municipalities, for instance, in reducing such material to saleable chips. Chipping machines constructed according to the present invention are particularly adapted to be manually fed.

In prior art drum-type machines the knife drum rotates at a high velocity, i.e. in the neighborhood of 3000 r.p.m., causing the material being chipped to be drawn into the chipping disc at a high feed rate, i.e., 250 to 600 feet per minute. When an individual manually feeds limbs to such a machine, he cannot satisfy this high rate of feed, and thus the machine cannot be operated efficiently. Moreover, the horsepower available in such machines substantially exceeds that required to accommodate manual feeding. Further, ifa workmans clothing, gloves, or the like, become inadvertently caught in the material being fed at the high rate, i.e. in

excess of 100 feet per minute, it is difficult for the workman to react sufficiently quickly to avoid being drawn with the clothing into the chipper.

Another safety factor to consider in manually fed chippers is the possibility of material backfire. Before the chipping disc commences to cut brush, it sometimes causes the brush to backfire, forcing it toward the workman. If the chipping disc is traveling at a very high rate, the material is backfired at a very high rate and may cause serious injury.

Accordingly, it is an object of the present invention to provide apparatus for reducing limbs, brush, and the like to chips, which can be safely, manually fed.

It is another object of the present invention to provide chipping apparatus of the type described which utilizes a feed rate matching the work rate of an ordinary workman and will efficiently operate when being manually fed.

Revolving chipper members which travel at high rotational velocities, Le. 3000 r.p.m., require dynamic balancing. It is an object of the present invention to provide chipping apparatus which need not be dynamically balanced.

Prior art machines are also known in which chipping discs mount a plurality of circumferentially spaced, radially disposed cutting or chipping knives and include a plurality of radially disposed slots extending axially through the disc to axially pass the chips. Such discs are normally keyed on precision machined drive shafts. Because of the manner in which such prior art shafts and discs are coupled, the slots and cutting knives cannot intersect the central axis of the chipping disc. Moreover, if the rotational velocity of a multi-bladedisc is decreased so that the feed rate at which the material is drawn into the machine matches the manual feed capability of an individual, the knives cut through the wood at such a low speed that they tear and crush the fiber edges of the chips, rather than cleanly cutting the wood into chips. Such crushed chips are unacceptable for many applications and are not saleable for them.

It is a further object of the present invention to provide a rotary cutting disc mounting a single cutting knife having a leading cutting edge which can extend to intersect the rotational axis of the disc.

Another object of the present invention is to provide apparatus of the type described having a rotary chipping disc with a generally radially disposed cutting knife extending along an axial slot which extends through the disc for passing chips cut by the knife.

With apparatus constructed according to the present invention, the disc includes a radially disposed, axial slot intersecting the rotational axis of the disc and a chipping knife having a leading edge extending through the rotational axis, thus permitting a smaller diameter disc to be utilized than has been previously required.

It is still another object of the present invention to provide chipping apparatus of the type described having a vertically inclined chipping disc, a downwardly, forwardly inclined feed chute upstream of the disc, and a feed roll supported above the chute for feeding the material to be chipped in a downwardly, forwardly inclined path of travel to the disc to crowd the material toward the disc. The crowding of material into the chipping disc prevents brush and the like from bouncing back, or backfiring, toward the operator. thus resulting in a safer operation.

These, and other objects of the present invention, will become apparent to those of ordinary skill in the art as the description thereof proceeds.

SUMMARY OF THE INVENTION Apparatus for reducing trees, brush, branches, and the like to chips wherein material to be chipped fed toward a chipping disc having a single, generally radially disposed cutting knife thereon, which is rotated at such a speed that material being chipped will be drawn toward the chipping disc at a rate of feed which will match the working feed rate of an ordinary workman.

The present invention may more readily be described by reference to the accompanying drawings, in which:

FIG. 1 is a side elevational view of chipping apparatus constructed according to the present invention, parts of the frame being broken away to more clearly illustrate other portions of the apparatus;

FIG. 2 is a partly sectional, rear elevational view of the chipping apparatus, taken along the line 22 of FIG. 1, part of a feed apron for supporting material to be chipped being broken away to more clearly illustrate an overhead feed roll",

FIG. 3 is a rear end view particularly illustrating the chipping disc, taken along the line 3-3 of FIG. 1;

FIG. 4 is a top plan view, taken along the line 44 of FIG. 1; and

FIG. 5 is a schematic diagram of a fluid control circuit for controlling the operation of the apparatus illustrated in FIGS. l-4.

Apparatus constructed according to the present invention is mounted on a portable frame, generally designated F, supported for movement by groundengaging wheels 10 mounted on a frame supported axle 11, as usual. The frame F includes a hitch (not shown) for attachment to a draft vehicle, such a tractor or the like. The frame F mounts a chipper-housing or casing, generally designated 12, including a pair of axially spaced, from and rear end walls 14 and I6 spanned by a generally cylindrical side wall 18. A chip discharge spout 20 is mounted atop the wall 18 for directing chips S to a discharge location.

A cutter head or chipper assembly, generally designated 26 and disposed in the chipper housing 12, is mounted on a drive shaft, generally designated 22,

which extends through an opening 14a in the front end wall 14 and is journaled for rotation about an axis a by frame supported bearings 24. The chipper head assembly 26 includes a cylindrical chipper disc 32 having its forward face 32a welded, at 34 (FIG. 3) to the drive shaft 22, and a plurality of equiangularly spaced fan blades 28 welded at 29 to the shaft 22 and to the forward face 32a of the chipper disc 32. It is important to note that the shaft 22 is fixed to the fan blades 28 and to the disc 32 and does not journal the disc 32 or the fan blades 28.

The chipper disc 32 includes a single, radially disposed chip passing slot 36 located substantially equiangularly between a pair of the fan blades 28. The slot 36, which passes axially through the disc 32, extends radially from the periphery of the disc, and terminates a slight distance d radially beyond the rotational axis a of the disc. The weld 34 between the chipping disc 32 and the shaft 22 is interrupted by the slot 36. A radially disposed, axial recess 39 is provided in the chipping disc 32 adjacent the slot 36 and receives a radially disposed wood cutting or chipping knife 40, which is fixed to the disc by a plurality of bolts 42, for cutting brush, trees, branches, and the like, generally designated B, into chips S that axially pass through the slot 36. The leading edge 40a of the wood cutting knife 40, which is axially upstream or rearward of the upstream or rearward face 32b of the cutting disc 32, intersects the rotational axis of the disc 32. The radially inner end of the leading cutting edge 40a projects a small distance d, i.e. onefourth inch, beyond the rotational axis a of the disc 32. The chip size can be varied by varying the width of the cutting knife 40.

The rear end wall 16 of the chipper housing 12 includes an axial opening 27 which, for a 3 foot diameter cutting disc 32, may typically be l6 inches wide and l inches high. The lower border surface 27a of the opening 27 is generally horizontal and positioned approximately 1% inches below a horizontal plane p intersecting the rotational chipper disc axis a. As the cutting knife moves downwardly, it will force the material B being chipped against the border surface 27a which acts as an anvil. If the border surface 27a is spaced more than 1 /2 inches above or below a horizontal plane intersecting the axis a, the material B will be thrown sidewisely, either toward or away from the axis a depending on the relative positions of the various parts and the material being chipped.

Apparatus for rotating the cutterhead drive shaft 22 and the cutterhead assembly 26 comprises a belt 43 which is trained around a pulley 44, fixed to the end of the drive shaft 22, and a pulley 46 fixed to the end of a shaft 48 journaled in frame supported bearings 49. The shaft 48 is coupled to a drive shaft 49a via a universal coupling member 52 which is driven by a frame supported, gasoline powered engine, schematically designated 50.

Provided upstream or rearward of the cutter head assembly 26 is a feed assembly, generally designated 54, comprising a pair of axially spaced apart mounting plates 56 (F168. 2 and 4), spanned by a pair of side plates 60 and 62. The feed assembly 54 is swingably mounted on a shaft 58 having a rotational axis b positioned at one side of, and extending generally parallel to, the chipping disc axis a. The shaft 58 is journaled by frame supported bearings 61.

A feed roll, generally designated 66, is mounted for rotation on the side plates 60 and 62 by a shaft 68. The feed roll 66 is driven by a gear wheel 70 meshing with a gear wheel 72 fixed to the output shaft 71 of a hydraulic motor 74, carried by one of the frame plates 56. The feed roll 66 includes a cylindrical drum 76 having a plurality of circumferentially spaced, toothed or serrated blades or plates 78 on its periphery. The feed roll 66 is driven in the direction represented by the arrow 0 (H6. 1 about the axis x of the shaft 68 to feed limbs. branches, and small diameter trees, all of which are under about ten inches in diameter, brush, and the like, generally designated B, toward the chipper assembly 26. The feed roll 66 is so mounted or extends to a position in which it is positioned on the side of disc axis a opposite axis 12 and overlies the center 0 of the branch B being chipped so that it will be generally longitudinally aligned with the opening 27 in the rear housing wall 16. Since the rotational velocity of the chipping knife portion intersecting the disc axis a is zero, this portion of the knife does not effectively cut large diameter material B. It will, however, sever and dislodge small branches which tend to jam in the radially inner portion of opening 27. The material B tends to be urged radially away from the disc axis a to a position between the periphery and rotational axis of disc 32, by the feed roll 66 which is upwardly, outwardly inclined when it is feeding the material B.

The feed assembly 54 also includes a curvilinear chute or support apron 80 for supporting and guiding material B to be chipped for movement, in the direction of the arrow g, toward the chipper disc 32. The apron 80 has a portion 81 adjacent the chipping disc 32 which is forwardly inclined at a l5 angle e to a horizontal plane p and the chipping disc 78 is forwardly inclined at a 30 anglefrelative to a vertical plane v. The included angle between the cutting disc 32 and the terminal portion 81 of the chute 80 thus is 60 and the knife edge will accordingly always avoid taking a perpendicular cross grain cut.

Counterweights, generally designated 82, are fixed to one of the feed assembly side plates 62 to normally downwardly bias the feed assembly 54 to the position illustrated in FIG. 2 against a pair of stops 86 and 88 mounted on the frame F If the material B being chipped increases in diameter, the feed assembly 54 automatically rides up over it, pivoting the entire feed assembly' 54 upwardly to the chain line position illustrated in FIG. 2. A wall 89 is welded between the pair of fan blades 28 which substantially border chip slot 36 and functions as a static balancing device. lt is situated directly axially behind the slot 36 and is of comparable weight to the material removed to form slot 36.

Referring now more particularly to FIG. 5, the control circuit is illustrated and includes a hydraulic pump 90 which is driven by the diesel engine 50 driving the chipping unit 26. The pump 90 is connected in circuit with the hydraulic motor 74 for driving the feed roll 66 of the unit 54. The hydraulic motor 74 may be of the type manufactured by Charllynn Company, of Minneapolis, Minnesota, as Model No. 3000. The pump 90 pumps fluid from a reservoir 92 through a line 93 to a pilot-operated valve, generally designated 94, including a main valve and a pilot valve 96. The valve 94 may be of the type manufactured by Rivett, lnc., of Pewaukee, Wisconsin, as Model No. 6656. When the valve 94 is deenergized, fluid flows from the line 93 through the main valve 95 to a line 97, and then to a reservoir 98. The pilot valve 96 is connected between a reservoir 99 and the pump 90 by a line 100, which is connected to the output of the pump 90. A relief valve 101 is connected between the line 93 and a reservoir 106 for relieving the pressure in line 93 when it builds to a predetermined pressure.

A solenoid 103 for moving the fluid control spool of the pilot valve 96 to the flow-through position is connected with a suitable source of power, such as a DC. battery 131, which causes the spool of the pilot valve 96 to move to the flow-through position. When this happens hydraulic fluid will flow from the line 100 through the line 107 to move the control spool of the main valve 95 to the flow-through position so that fluid will flow from the line 93 through the hydraulic motor 74 and then to the reservoir 98 through the line 97. A solenoid 110 on the pilot valve 96 is adapted to be connected across the source of power via a switch 133. When energized, the solenoid 110 moves the spool of the pilot valve 96 to the cross-over position so that the hydraulic fluid flows from the line 100 through the line 108 to move the main valve 95 to the cross-over position. When this happens, fluid from the pump 90 passes through the line 93 and the motor 74, in a reverse direction, to drive the feed roll 66 in the opposite direction. The reversely flowing fluid then passes to the reservoir 98 via a line 93. By selectively connecting the solenoids 103 and 110 in circuit, the feed roll 66 can be selectively operated in the forward or reverse directions. Both the chipper disc 32 and drive roll 66 are directly responsive to the speed of rotation of the diesel engine 50 and thus the speed of rotation of the drive roll 66 is timed with the rotation of the chipper disc 32. If rotation of the disc is halted by a foreign object, the diesel engine 50 will stop, and thus the feed roll 66 will also stop. The feed roll 66 can be manually independently stopped if desired by manually closing the switch 133 to energize the solenoids 103 and 110.

THE OPERATION Material B to be chipped, such as branches, limbs,

.brush and the like, are manually fed to the feed Wheel 66 which is rotating in the direction of the arrow c to propel it into the rotating chipper disc 32 where it is cut into chips S by the chipping or cutting knife 40. The chips axially pass through the slot 36 into the enclosure defined by the disc 32, the counterweight rear wall 89, and the fan blades 28 bordering the slot 36. The chips S will be discharged radially outwardly through the discharge chute by the fan blades 28, as they pass the chute 20, into the airstream created by the rapidly rotating fan blades 28. The cutting disc 32 and the feed plate 40 are relatively inclined such that the cutting blade 40 will not cut directly cross-grain, but will cut longitudinally forwardly at an inclined angle not normal to the grain to pull the tree trunks B downwardly and forwardly toward the chipper disc 32 as it cuts therethrough. If the butt end of the limb of a tree B is first inserted, the draw" of the vertically inclined disc 32 alone will cause the machine to be self-feeding. lf non-condensed material, such as branches, brush, and the like, constitute the material B to be cut, the feed roll 66 will tend to bunch the material and cram it toward the disc 32. The rotational speed of the disc 32, which has the single elongate cutting edge 40a, is timed to produce a linear material feed rate in the range 20-85 feet per minute. It has been found that in making standard three-fourth inch length chips, approximately l50 horsepower is required to rotate in a 3-foot diameter chipping blade at a rotational velocity of 1,000 rpm. so that a lO-inch diameter green'branch or the like, which is about maximum diameter for the machine, is drawn in at a feed rate of feet per minute. If the chipper disc 32 is driven at 900 rpm, an optimum feed rate of 51 feet per minute is achieved, the feed rate reducing proportionately with ther.p.m. If the rotational velocity of the disc is lowered such that a feed rate of 20 feet per minute is achieved, only 50 horsepower is required.

When a jam-up occurs and the disc or wheel 32 is halted or appreciably slowed, the operator can reverse the direction of feed of wheel 66 to back the material sufficiently away from the disc 32 to permit full speed forward feeding movement to again be achieved. The lever operated switch 133 provided for this purpose is shown in FIG. 5 and is connected to valve 94 to accomplish this.

Because the radial wall 89 spanning the set of fan blades 28 axially opposite the slot 36 is of a weight to balance out the material which has been removed to form the slot 36, the disc structure isin axially static balance and wall 89 also is operative to trap chips in view of its position in back of the slot 36.

Finally, because the rotational axis of the feed wheel 66, in operation, is disposed at an angle relative to the edge 27a of the opening 27, when a limb or branch is disposed below it and being fed toward disc 32, the feed wheel 66 tends to crowd the limb or branch being fed radially outwardly relative to the disc axis a and the pivot axis [2, to a position in which the branch B is positioned between the periphery and axis of the disc 32, centered in the opening 27. Of course, this camming increases as the diameter of' the limb being fed increases and the angularity of disposition of wheel 66 increases.

It is to be understood that the drawings and descriptive matter are in all cases to be interpreted as merely illustrative of the principles of the invention, rather than as limiting the same in any way, since it is contemplated that various changes may be made in various elements to'achieve like results without departing from the spirit of the invention or the scope ofthe appended claims.

What is claimed is:

1. Apparatus for reducing material such as trees, brush, and the like to chips comprising:

a frame provided with a chipping station;

means on said frame for conveying said material forwardly toward said chipping station; and

chipping means on said frame at said chipping station for cutting said forwardly moving material into chips, including a chipping disc, having an upstream rear face and a downstream front face, rotatable about an axis,

a single, generally radially disposed, chipping knife means mounted on said disc for cutting said forwardly moving material into chips at said chipping station as said chipping disc rotates;

said disc being unslotted except for a single slot extending from said rear'face to said front face adjacent said knife means to receive and axially forwardly pass said chips; and

means fixed for rotation with said disc downstream of said slot and generally axially aligned therewith for statically balancing said chipping means.

2. The apparatus of claim 1 including a plurality of generally radially disposed, circumferentially spaced, fan blades mounted to the rear face of said disc for expelling said chips.

3. The apparatus set forth in claim 2 wherein said static balancing means comprises a radial wall spanning a pair of said fan blades on circumferentially opposite sides of said slot to provide an enclosure for said chips.

4. The apparatus set forth in claim 3 including a shaft rotatable on said frame about its axis, said fan blades being welded to said shaft for rotation therewith, and said disc being welded to said blades.

5. The apparatus set forth in claim 1 wherein the leading edge of said blade means intersects the rotational axis of said chipping disc.

6. The apparatus set forth in claim 1 including means for rotating said disc at such a velocity as to draw the material axially toward the disc at achipping rate within the range of 20 to 85 feet per minute.

7. The apparatus set forth in claim 1 including a feed plate upstream of said disc having a feed opening at one lateral side of said axis and providing a generally horizontal support surface for said material being chipped.

8. The apparatus of claim 7 including means for driving said disc in such a direction that said material is driven downwardly by said chipping knife means toward said support surface.

9. The apparatus of claim 1 wherein said disc is vertically inclined so that the lower half of said disc is downstream of the upper half of said disc, said conveying means including a downwardly forwardly inclined material feed chute, and rotatable feed roll means positioned above said chute for cramming said material toward said disc.

10. The apparatus of claim 9 wherein means is provided for mounting said feed roll for swinging movement about an axis generally parallel to said first mentioned axis.

11. The apparatus of claim 10 wherein said feed roll is so mounted that it tends to move said material in a path generally parallel to the rotational axis of said chipping disc.

12. Apparatus for reducing material such as trees, brush and the like, to chips comprising:

a frame with a chipping station;

a knived chipper disc mounted on said frame at said chipping station for rotation about a vertically inclined axis so that the upper half of said disc is upstream of the lower half of said disc;

means for conveying said material to said chipping station, including a downwardly inclined material support chute, and

endless drive means on said frame above said support chute for vertically engaging the material on said support and moving it forwardly toward said chipper disc;

said endless drive means'being pivoted for vertical swinging movement about a longitudinal axis at one side of said chute, said endless drive means extending to a position on the opposite side of said vertically inclined axis to urge the material being fed away from said rotational axis and said longitudinal axis.

13. The apparatus of claim 12 including a feed plate upstream of said disc having a feed opening at said opposite side and generally above said rotational axis; said chute being generally longitudinally aligned with said opening, said disc including a chipping knife extending generally radially outwardly from the rotational axis of said disc; and means is provided for driving said disc about said rotational axis in a direction to move said chipping knife in a path to force said material forwardly toward said supply chute.

14. The apparatus of claim 12 wherein said longitudinal axis is generally above a horizontal plane intersecting the axis of said chipping disc.

15. Apparatus for reducing material such as trees, brush and the like, to chips comprising:

a frame with a chipping station;

a knived chipper disc mounted on said frame at said chipping station for rotation about a rotational axis;

a material supply chute positioned at one side of said rotational axis for directing material to be chipped to a position between the periphery and rotational axis of said disc;

means for conveying said material to said chipping station, including material support means, and endless drive means on said frame above said support chute for vertically engaging the material on said support means and moving it forwardly toward said chipper disc;

said endless drive means being pivoted for vertical swinging movement about a longitudinal axis at the opposite side of said rotational axis and extending to a position on said one side of said rotational axis to urge the material being fed away from said rotational axis and said longitudinal axis.

16. Apparatus for reducing material such as trees. brush, and the like to chips comprising: a frame; a shaft rotatably mounted about a longitudinal axis on said frame; means mounting said shaft on said frame; a generally longitudinally extending feed bed on said frame; a powered feed member for said feed bed for moving material along said feed bed; a reversible drive for said feed member for selectively withdrawing as well as advancing material; a chipper disc, extending in a plane generally crosswise of said feed bed and having axially spaced end faces, fixed to said shaft for rotation therewith, said disc having a working face portion confronting said material on the feed bed which is substantially imperforate except for a single generally radially disposed slot extending from one axial end face of said disc to the other axial end face of said disc; a generally radially disposed single chipper knife blade mechanism on said disc generally adjacent said slot for cutting said material into chips and angularly disposed to said feed bed for axially drawing said material along said feed bed toward said disc; and means for rotating said knife mechanism and operating said feed member drive at a correlated rate considering the angular disposition of said single knife mechanism sufficient to draw the material forwardly at a predetermined linear speed to enable the single angularly disposed knife blade mechanism to reduce it to chips, and to selectively withdraw said material.

17. The apparatus of claim 16 wherein said shaft is rotated at a rate which will draw said material toward said disc at 5l feet per minute.

18. The apparatus as set forth in claim 16 wherein said predetermined speed is substantially to 85 feet per minute.

19. The apparatus as set forth in claim 16 wherein means, fixed for rotation with said disc downstream of said slot and generally axially aligned therewith, is provided for statically balancing said knife mechanism.

20. The apparatus as set forth in claim 19 wherein a plurality of generally radially disposed, circumferentially spaced fan blades are mounted at the rear face of said disc for expelling said chips, and said means for statically balancing said knife mechanism comprises a radial wall spanning a pair of fan blades which are located on circumferentially opposite sides of said slot to provide an enclosure for said chips.

21. The apparatus as set forth in claim 20 wherein said fan blades are welded to said shaft for rotation therewith, and are also welded to said disc, and said disc is welded to said shaft.

22. The apparatus as set forth in claim'l6 wherein said knife mechanism has a leading edge which substantially intersects the rotational axis of said chipping disc.

23. The apparatus as set forth in claim 16 wherein said disc is angularly disposed in a vertically inclined plane so that the lower half of said disc is downstream of the upper half of said disc.

24. The apparatus as set forth in claim 16 wherein said feed member includes a rotatable roll pivoted for vertical swinging movement about a longitudinal axis at one side of said feed bed and disc axis, and extends to a position on the opposite side of said disc axis at an inclined angle with said feed bed to cam said material radially away from said disc axis.

25. The apparatus as set forth in claim 24 wherein that said axis about which the roll swings is generally above a horizontal plane intersecting the axis of said chipping disc.

26. The apparatus as set forth in claim 25 wherein the lower end of said feed bed includes an opening in a stationary cover for said chipper disc having a generally horizontal support surface for material being chipped which extends in a horizontal plane substantially at the level of a horizontal plane through said axis.

27. The apparatus of claim 26 wherein said opening terminates at its radially inner marginal edge short of a vertical plane through the axis of rotation of said chipper disc.

28. Apparatus for reducing material such as trees, brush, and the like to chips comprising: a frame, a shaft rotatably mounted about a longitudinal axis on said frame; means mounting said shaft on said frame; a generally longitudinally extending feed bed on said frame; a chipper disc assembly, including a disc on said shaft and an entrance chute at one side of said axis, said disc extending in a plane generally crosswise of said feed bed and having axial spaced end faces, fixed to said shaft for rotation therewith, said disc having a working face portion confronting said feed bed which has a generally radially disposed slot extending from one axial end face of said disc to the other axial end face of said disc; a generally radially disposed chipper knife blade mechanism on said disc generally adjacent said slot for cutting said material into chips and angularly disposed for axially drawing said material along said feed bed toward said disc; a subframe mounted on said frame; a powered roll member rotatably mountedon said subframe above said feed bed for moving material along said feed bed toward said disc; said subframe being pivoted for vertical swinging movement about a longitudinal axis at one side of the disc axis in a position to dispose a portion of the roll on the opposite side of the disc axis in general alignment with said chute and at an inclined angle with said feed bed to cam the material radially away from the disc axis; a reversible drive for said roll member for selectively withdrawing as well as advancing material; and means for rotating said knife mechanism and operating said feed member drive at a correlated rate'considering, the angular disposition of said knife mechanism sufficient to draw the material forwardly at a predetermined linear speed to enable the angularly disposed knife blade mechanism to reduce the material to chips, and to selectively withdraw said material.

29. The apparatus as set forth in claim 28 wherein the axis about which the subframe pivots is generally above a horizontal plane intersecting the chipping disc axis of rotation.

30. The apparatus as set forthin claim 28 in which said chute lower edge extends in a substantially horizontal plane substantially at the level of the axis of rotation of the chipping disc. 

1. Apparatus for reducing material such as trees, brush, and the like to chips comprising: a frame provided with a chipping station; means on said frame for conveying said material forwardly toward said chipping station; and chipping means on said frame at said chipping station for cutting said forwardly moving material into chips, including a chipping disc, having an upstream rear face and a downstream front face, rotatable about an axis, a single, generally radially disposed, chipping knife means mounted on said disc for cutting said forwardly moving material into chips at said chipping station as said chipping disc rotates; said disc being unslotted except for a single slot extending from said rear face to said front face adjacent said knife means to receive and axially forwardly pass said chips; and means fixed for rotation with said disc downstream of said slot and generally axially aligned therewith for statically balancing said chipping means.
 2. The apparatus of claim 1 including a plurality of generally radially disposed, circumferentially spaced, fan blades mounted to the rear face of said disc for expelling said chips.
 3. The apparatus set forth in claim 2 wherein said static balancing means comprises a radial wall spanning a pair of said fan blades on circumferentially opposite sides of said slot to provide an enclosure for said chips.
 4. The apparatus set forth in claim 3 including a shaft rotatable on said frame about its axis, said fan blades being welded to said shaft for rotation therewith, and said disc being welded to said blades.
 5. The apparatus set forth in claim 1 wherein the leading edge of said blade means intersects the rotational axis of said chipping disc.
 6. The apparatus set forth in claim 1 including means for rotating said disc at such a velocity as to draw the material axially toward the disc at a chipping rate within the range of 20 to 85 feet per minute.
 7. The apparatus set forth in claim 1 including a feed plate upstream of said disc having a feed opening at one lateral side of said axis and providing a generally horizontal support surface for said material being chipped.
 8. The apparatus of claim 7 including means for driving said disc in such a direction that said material is driven downwardly by said chipping knife means toward said support surface.
 9. The apparatus of claim 1 wherein said disc is vertically inclined so that the lower half of said disc is downstream of the uppeR half of said disc, said conveying means including a downwardly forwardly inclined material feed chute, and rotatable feed roll means positioned above said chute for cramming said material toward said disc.
 10. The apparatus of claim 9 wherein means is provided for mounting said feed roll for swinging movement about an axis generally parallel to said first mentioned axis.
 11. The apparatus of claim 10 wherein said feed roll is so mounted that it tends to move said material in a path generally parallel to the rotational axis of said chipping disc.
 12. Apparatus for reducing material such as trees, brush and the like, to chips comprising: a frame with a chipping station; a knived chipper disc mounted on said frame at said chipping station for rotation about a vertically inclined axis so that the upper half of said disc is upstream of the lower half of said disc; means for conveying said material to said chipping station, including a downwardly inclined material support chute, and endless drive means on said frame above said support chute for vertically engaging the material on said support and moving it forwardly toward said chipper disc; said endless drive means being pivoted for vertical swinging movement about a longitudinal axis at one side of said chute, said endless drive means extending to a position on the opposite side of said vertically inclined axis to urge the material being fed away from said rotational axis and said longitudinal axis.
 13. The apparatus of claim 12 including a feed plate upstream of said disc having a feed opening at said opposite side and generally above said rotational axis; said chute being generally longitudinally aligned with said opening, said disc including a chipping knife extending generally radially outwardly from the rotational axis of said disc; and means is provided for driving said disc about said rotational axis in a direction to move said chipping knife in a path to force said material forwardly toward said supply chute.
 14. The apparatus of claim 12 wherein said longitudinal axis is generally above a horizontal plane intersecting the axis of said chipping disc.
 15. Apparatus for reducing material such as trees, brush and the like, to chips comprising: a frame with a chipping station; a knived chipper disc mounted on said frame at said chipping station for rotation about a rotational axis; a material supply chute positioned at one side of said rotational axis for directing material to be chipped to a position between the periphery and rotational axis of said disc; means for conveying said material to said chipping station, including material support means, and endless drive means on said frame above said support chute for vertically engaging the material on said support means and moving it forwardly toward said chipper disc; said endless drive means being pivoted for vertical swinging movement about a longitudinal axis at the opposite side of said rotational axis and extending to a position on said one side of said rotational axis to urge the material being fed away from said rotational axis and said longitudinal axis.
 16. Apparatus for reducing material such as trees, brush, and the like to chips comprising: a frame; a shaft rotatably mounted about a longitudinal axis on said frame; means mounting said shaft on said frame; a generally longitudinally extending feed bed on said frame; a powered feed member for said feed bed for moving material along said feed bed; a reversible drive for said feed member for selectively withdrawing as well as advancing material; a chipper disc, extending in a plane generally crosswise of said feed bed and having axially spaced end faces, fixed to said shaft for rotation therewith, said disc having a working face portion confronting said material on the feed bed which is substantially imperforate except for a single generally radially disposed slot extending from one axial end face of said disc to the other aXial end face of said disc; a generally radially disposed single chipper knife blade mechanism on said disc generally adjacent said slot for cutting said material into chips and angularly disposed to said feed bed for axially drawing said material along said feed bed toward said disc; and means for rotating said knife mechanism and operating said feed member drive at a correlated rate considering the angular disposition of said single knife mechanism sufficient to draw the material forwardly at a predetermined linear speed to enable the single angularly disposed knife blade mechanism to reduce it to chips, and to selectively withdraw said material.
 17. The apparatus of claim 16 wherein said shaft is rotated at a rate which will draw said material toward said disc at 51 feet per minute.
 18. The apparatus as set forth in claim 16 wherein said predetermined speed is substantially 20 to 85 feet per minute.
 19. The apparatus as set forth in claim 16 wherein means, fixed for rotation with said disc downstream of said slot and generally axially aligned therewith, is provided for statically balancing said knife mechanism.
 20. The apparatus as set forth in claim 19 wherein a plurality of generally radially disposed, circumferentially spaced fan blades are mounted at the rear face of said disc for expelling said chips, and said means for statically balancing said knife mechanism comprises a radial wall spanning a pair of fan blades which are located on circumferentially opposite sides of said slot to provide an enclosure for said chips.
 21. The apparatus as set forth in claim 20 wherein said fan blades are welded to said shaft for rotation therewith, and are also welded to said disc, and said disc is welded to said shaft.
 22. The apparatus as set forth in claim 16 wherein said knife mechanism has a leading edge which substantially intersects the rotational axis of said chipping disc.
 23. The apparatus as set forth in claim 16 wherein said disc is angularly disposed in a vertically inclined plane so that the lower half of said disc is downstream of the upper half of said disc.
 24. The apparatus as set forth in claim 16 wherein said feed member includes a rotatable roll pivoted for vertical swinging movement about a longitudinal axis at one side of said feed bed and disc axis, and extends to a position on the opposite side of said disc axis at an inclined angle with said feed bed to cam said material radially away from said disc axis.
 25. The apparatus as set forth in claim 24 wherein that said axis about which the roll swings is generally above a horizontal plane intersecting the axis of said chipping disc.
 26. The apparatus as set forth in claim 25 wherein the lower end of said feed bed includes an opening in a stationary cover for said chipper disc having a generally horizontal support surface for material being chipped which extends in a horizontal plane substantially at the level of a horizontal plane through said axis.
 27. The apparatus of claim 26 wherein said opening terminates at its radially inner marginal edge short of a vertical plane through the axis of rotation of said chipper disc.
 28. Apparatus for reducing material such as trees, brush, and the like to chips comprising: a frame, a shaft rotatably mounted about a longitudinal axis on said frame; means mounting said shaft on said frame; a generally longitudinally extending feed bed on said frame; a chipper disc assembly, including a disc on said shaft and an entrance chute at one side of said axis, said disc extending in a plane generally crosswise of said feed bed and having axial spaced end faces, fixed to said shaft for rotation therewith, said disc having a working face portion confronting said feed bed which has a generally radially disposed slot extending from one axial end face of said disc to the other axial end face of said disc; a generally radially disposed chipper knife blade mechanism on said disc generally adjacent said slot for cutting said material into chips and angularly disposed for axially drawing said material along said feed bed toward said disc; a subframe mounted on said frame; a powered roll member rotatably mounted on said subframe above said feed bed for moving material along said feed bed toward said disc; said subframe being pivoted for vertical swinging movement about a longitudinal axis at one side of the disc axis in a position to dispose a portion of the roll on the opposite side of the disc axis in general alignment with said chute and at an inclined angle with said feed bed to cam the material radially away from the disc axis; a reversible drive for said roll member for selectively withdrawing as well as advancing material; and means for rotating said knife mechanism and operating said feed member drive at a correlated rate considering the angular disposition of said knife mechanism sufficient to draw the material forwardly at a predetermined linear speed to enable the angularly disposed knife blade mechanism to reduce the material to chips, and to selectively withdraw said material.
 29. The apparatus as set forth in claim 28 wherein the axis about which the subframe pivots is generally above a horizontal plane intersecting the chipping disc axis of rotation.
 30. The apparatus as set forth in claim 28 in which said chute lower edge extends in a substantially horizontal plane substantially at the level of the axis of rotation of the chipping disc. 